A conventional golf club head has a thick metal face plate to sustain the impact of the golf ball during play. The rest of the head is hollow, having thin walls supported by peripheral rims so that the head can have large moment of inertia about its center of gravity. The thickness of the face plate, for wood and iron drivers, have not been specified in literature. Measurements of conventional face plates yield about 2.0 to 4.0 mm in the central impact areas of these face plates.
Since a golf ball and the face plate of the head are made of hard materials, the contact area of both bodies during impact is very small, and the peak force at impact is large. The time of contact is extremely short, about a few thousandth of a second. As a result, dynamic energy of the head transmitted to the ball suffers considerable loss. In addition, surface irregularity affects accuracy, and the orientation of the resultant force which drives the ball towards the intended direction is difficult to control.